Electrical snap switches



y 8, 1956 A. w. KRIEGER ELECTRICAL SNAP SWITCHES Filed Dec. 12, 1952 & I

United States Patent ELECTRICAL SNAP SWETCHES Alvin W. Krieger, Hammer, Inc., ware Milwaukee, Wis., assignor to Cutler- Milwaukee, Wis., a corporation of Dela- This invention relates to improvements in electric snap switches, and more particularly toggle lever operated switches adapted for one-hole mounting.

Heretofore it was found necessary to employ relatively large or massive current carrying parts in switches intended for control of large current flow. Such large parts were considered necessary to withstand the severe arcing incident to interrupting such circuits; with resultant relatively large size of such switches. Certain electrical appliances afford very little space for the circuit controlling switch; and it was found undesirable and uneconomical to increase the size of the switch to correspond with the increased power demand of the appliance. It is, therefore, a primary object of this invention to provide a small, compact switch having relatively light component parts which can be used to interrupt high capacity circuits due to rapid extinction of any electric arcs generated.

Another object is to provide a switch of the aforementioned character having an unusually high rating or current controlling capacity whereby the same may be employed in lieu of the larger and more expensive switches of the prior art.

Another object is to generally improve the form and arrangement of the parts of switches of the aforementioned character whereby the above and other objects are attained.

Another object is to provide a movable contactor and combined stationary contact and terminal members of novel form, in conjunction with novel means for supporting the same in cooperative relationship to each other.

Another object is to provide a high capacity switch wherein electric arcing is reduced to a minimum.

Another object is to provide a substantially enclosed chamber for the stationary and movable contact members of the snap switch; said chamber being formed of arc resisting material.

The novel features which I consider characteristic of my invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of a specific embodiment when read in connection with the accompanying drawings, in which:

Fig. l is a vertical sectional view, taken along the iongitudinal center line, and showing the switch parts in assembled relation.

Fig. 2 is a top plan view of the molded insulating switch base, together with the combination contact and terminal members, a bridging member, and a carrier for said bridging member.

Fig. 3 is an elevational view of the carrier.

Fig. 4 is a perspective view of the contactor.

Fig. 5 is a side elevational view of the carrier and bridging member in assembled relation; and

Fig. 6 is a plan view of the punched fibre insulating plate used for positioning the combination contact and terminal members.

2,744,302 Patented May 8, 1956 Similar reference characters indicate corresponding parts throughout the several views of the drawings.

Referring to the drawings, the numeral 10 designates a molded base formed of any suitable arc-resisting insulating material. In utilizing such a material I prefer to employ a composition consisting of melamine resin and an asbestos filler. As is well known, a switch base constructed of such material is effective to assist in rapidly extinguishing any electric arcs which come in contact therewith. Said base 10 is preferably of substantially rectangular form as illustrated, and the same is provided with a relatively deep substantially rectangular main recess 11 which opens to the upper surface thereof. As illustrated in Figs. 1 and 2, base 10 is provided with a pair of small recesses 12 and 13 each having pockets 12 and 13 to respectively receive, with a snug fit, the lower ends of combined stationary contact and terminal members 14 and 15, and to assist in positioning said contacts. A bridging contactor 16, having end portions 16 and 16 for cooperation with said stationary contacts, is positioned within said main recess 11 so that said end portions 16 and 16 are adapted to move into and out of said small recesses 12 and 13. As shown in Fig. 4 said contactor n6 is also formed with notches 16 and 16 and a slot 16 Contactor 16 is attached to a carrier member 17 which is formed with a tongue portion 17 of such size and shape as to fit Within said slot 16 Said carrier 17 is also formed with pivot projections 17 and 17 which snugly fit within notches 16 and L6 respectively of contactor 15, as shown in Fig. 5. Said carrier member 17 is also formed with shoulder portions 17' and 17 which bear against that portion of the contactor 16 which is beneath notches 16 and 16 to thus prevent any substantial relative movement between said contactor 16 and carrier 17. Such assembly is best illustrated in Fig. 5.

The ears 17 and 17 of carrier 17 are of such length as to also fit within open pivot bearings 18 and 19 respectively in the upper surface of base Such positioning of carrier 17 affords contactor 16 and carrier 17 an oscillatory movement with respect to said base. Carrier 17 is also formed with an upward projection l7 to assist in positioning lower end of a compression spring 20 (Fig. l), which seats against the edge portions 17 and 17 Fitted into the upper end of said coil spring 20 is an abutment member 21, which is preferably composed of molded insulating material; the upper end thereof being cupped or recessed as indicated in dotted lines in Fig. l to accommodate and provide a resilient bearing for the rounded lower end of a substantially cylindrical insulating plunger or pin 22. The upper end portion of plunger 22 is positioned within a correspondingly shaped recess in the lower end of an operating lever 23. Said lever 23 is pivotally attached to a bushing 24 as by means of a pin 25, the intermediate portion of which has a drive fit within an opening through said lever. The lower end portion or" said bushing 24 is of reduced outside diameter to fit within a circular opening in an upwardly offset portion of the metal top plate 26; said reduced portion or" bushing 24 being upset outwardly to rigidly unite the same with plate 26, as shown.

Positioned between said top plate 26 and the upper surface of base 10 are a pair of insulating plates 27 and 28. As shown in Fig. 6, insulating plate 28 is formed with a pair of longitudinal slots 23 and 28 for a purpose to be hereinafter described. Insulating plate 27 is similar to plate 28 except that it is not formed with slots such as 23 and 28 The entire assembly is held tcgether in any conventional manner, such as by means of bolts or rivets 29 extending through alined openings in plate 26 and members 27, 28, and 10.

The combined stationary contact and terminal members 14 and 15 are preferably punched from a strip or sheet of metal of good electrical conductivity such as copper, to the form shown in Figs. 1 and 2. The stationary contact portions are additionally formed to provide beveled portions 14 and 15 respectively to facilitate sliding engagement therewith of the flared end portions 16* and 16 of contactor lib. Also as shown in Figs. 1 and 2, the contact portions of members id and 3.5 are positioned within recesses formed in the side walls of the aforementioned recesses 12 and 13. Such positioning prevents any relative movement between members 14 and i5 and base it). As shown in Fig. l, the upper portions of members and 15' are formed so as to snugly fit within slots 28 and 28 of insulating plate 28. This, of course, further assists in positioning said stationary contacts. Since such portions of members 14 and 15 extend through the insulating plate 2.8, insulating plate 27 is provided between the metal top plate 21 and the aforementioned plate 28 so as to eliminate any possible shortcircuiting of members 14 and 15.

Members 14 and 15 are also formed with openings 14 and 15 respectively, for receiving any conventional electrical conductors. in this respect members 14 and 15 may be modified in any well known manner to afford other types of wiring terminal portions, such as are shown and described in Patent No. 1,998,962, which is assigned to the assignce of the present application.

Contactcr i6 is formed as shown in Fig. 4 and is composed of resilient sheet metal of good electrical conductivity. The end portions 1" and 16 are bent or flared our-.vardly to insure a good sliding engagement of said end portions against the stationary contact portions of members and i and against the inside walls of base ill when contactor 1'6 is disengaged from the stationary contacts; the tips of said end portions being bent inwardly toward each other or beveled as shown to insure proper sliding engagement thereof with members 14 and 15. As will be apparent, any arcs drawn between contactor 1d and members l t and will likewise, be brought into engagement with the inside wall portions of recess 11 in base 11 inasmuch as base it! is formed of arc resistini insulating material any resulting arcs will be cooled and rapidly extinguished, thus enabling utilization of switches employing the present invention in circuits having large current flow.

The aforementioned beveled surfaces 14 and 15 of members 14 and 15 facilitate movement of end portions 16 and lo of contactor 1d alternately into and out of engagment with the members 14 and 1S and the are resisting walls of the recess 11 in base it Members 14 and are not entirely ush with the walls of recess 11, but extend to some degree into the small recesses 12 and 13 to allow for a reasonable amount of contact wear.

As will be understood, a switch constructed in the manner herein disclosed is adapted for one-hole mounting within an opening provided in a panel, as by means of mounting nuts and 3K. Said nuts engage the threaded bushing 24 as shown in Fig. l, and when mounted are preferably positioned on opposite sides of a mounting panel in a well known manner.

When the operating lever 23 as shown in Fig. l is moved to the left, plunger 22 is moved to the right due to the pivotal action of lever 23 about pin This causes the assembly as shown in Fig. 5 to pivot about projections 17 and 17 in a clockwise direction to thereby effect movement of end portions 16 and 16 from contact with members and 15 into contact with the walls of small recesses and Such movement is, of course, a snap action as provided by the compression spring 2%. When the operating lever 23 is moved toward the right, the reverse snap action takes place, thereby causing the end portions lo slide across the walls of the small recesses 12 and i3 and into engagement with the beveled portions and 15 of the stationary contacts and the main body portions of members 1 and 15'.

Although i have shown and described certain specific embodiments of my invention, I am fully aware that many modifications thereof are possible. My invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the appended claims.

I claim:

1. In a high capacity single pole, single throw on and off electric snap switch, in combination, a molded base of arc-resisting insulating material having a recess opening to the upper surface thereof, said recess having a pair of substantially parallel opposite side walls, a pair of stationary contacts each being positioned partly within one of said side walls and having a portion formed with a beveled edge and extending into said recess, said stationary contacts being adapted for connection to an electric circuit to be controlled, a resilient bridging contactor pivotally supported within said recess and having a pair of opposed approximately parallel end portions biased laterally outwardly for engagement thereof jointly with said side walls and said stationary contacts sequentially, and operating means including a manually operable lever to effect pivotal snap movement of said contactor to thereby effect sliding movement of said end portions against said side walls and said stationary contacts, the arrangement being such that said end portions engage said stationary contacts with a greater degree of pressure than the degree of pressure thereof against said side walls.

2. In a high capacity single pole, single throw on and off electric switch, in combination, a molded insulating base of arc-resisting material formed with a main recess and a pair of small recesses communicating with said main recess, a stationary contact in each of said small recesses having a portion formed with a beveled edge and extending into said main recess, said stationary contacts each having a portion projecting from said base and adapted to be connected to an electric circuit to be controlled, a resilient bridging contactor pivotally supported within said main recess and having a pair of opposed approximately parallel end portions biased laterally outwardly, and operating means including a toggle lever pivotally supported relatively to said base and including an over-center spring between an end of said toggle lever and said bridging contactor to provide for sliding snap movement of said end portions across the side walls of said main recess, said beveled edges and the main body portions of said stationary contacts in sequence in response to opposite movements of said toggle lever in a manner to insure a relatively high degree of contact pressure between said end portions and the main body portions of said stationary contacts.

3. in a high capacity single pole, single throw on and off snap switch, in combination, a molded insulating base of arc-resisting material having a main recess and a pair of small recesses communicating with said main recess, said main and small recesses opening to the upper surface of said base, a stationary contact in each of said small recesses having a contact surface extending into said main recess, said stationary contacts each having a first portion projecting from said base and adapted for connection to an electric circuit to be controlled and a second portion extending above the upper surface of said base, a bridging contactor pivotally supported within said main recess and having substantially parallel resilient end portions, said end portions being inherently biased laterally outwardly toward said contact surfaces of the respective stationary contacts, operating means including a toggle lever pivotally supported relatively to said base and including an over-center compression spring between an end of said toggle lever and said bridging contactor to provide for sliding snap movement or" said end portions relatively to said contact surfaces and the side Walls of said recess in predetermined sequence in response to movements of said toggle lever in opposite directions respectively, to thereby effect rapid extinguishment of any resultant electrical arcs by drawing the same across the arc-resisting material of which said side walls are formed while providing for greater pressure of said contactor end portions against said stationary contacts than between said end portions and said recess side walls, and enclosure means for the upper surface of said base including an insulating plate having therein openings to closely fit the aforementioned second portions of said stationary contacts to assist in maintaining the same in a fixed position when assembled.

References Cited in the file of this patent UNITED STATES PATENTS 

